A brush for a brush motor is an electrically conductive component which slidably contacts a commutator to thereby form an electrical connection with the commutator so as to supply power to the rotor of the motor. Generally, the brush is square and mounted on a brush arm, and stays in tight contact with the commutator due to the elastic pushing force of a spring. The contact surface of a conventional brush that contacts the commutator is usually an arc surface that matches the outer surface of the commutator. In the first few times of operation of the brush motor, the contact surfaces of the brushes and the commutator may not fit well due to manufacturing tolerances and other factors, which may result vibration when the brush slides with respect to the commutator and therefore generating noise.